Etching of nanoscale structures

Abstract

A process for etching with an atomic force microscope using a two-dimensional metal chalcogenide as the substrate, is disclosed.

What is claimed is: 
     
       1. A process for etching a nanoscale structure using an atomic force microscope comprising scanning the microscope tip over a two dimensional substrate of at least one metal chalcogenide at a force of from about 10 -12  to about 10 -6  newtons to generate the controlled ablation of one or more molecular layers of the metal chalcogenide. 
     
     
       2. The process of claim 1 wherein a single molecular layer is ablated. 
     
     
       3. The process of claim 1 wherein more than one molecular layer is ablated simultaneously. 
     
     
       4. The process of claim 1 wherein the metal chalcogenide comprises InSe, ZrS 2 , TiSe 2 , SnSe 2 , SnS 2 , NbSe 2 , TaS 2 , MoSe 2 , or WSe 2  or solid solutions thereof. 
     
     
       5. The process of claim 4 wherein the metal chalcogenide comprises SnSe 2 , NbSe 2 , SnS 2 , or TaS 2 . 
     
     
       6. The process of claim 1 wherein the substrate comprises a layered material prepared by molecular beam epitaxy wherein at least one portion of the top layer is a two dimensional metal chalcogenide. 
     
     
       7. The process of claim 6 wherein the metal chalcogenide comprises InSe, ZrS 2 , TiSe 2 , SnSe 2 , SnS 2 , NbSe 2 , TaS 2 , MoSe 2 , or WSe 2 . 
     
     
       8. The process of claim 1 wherein the structure etched can be viewed simultaneously with its creation. 
     
     
       9. The process of claim 1 wherein the depth of the etched structure is controlled to a precision of (0.0003 ×n) nanometer, wherein n is the number of layers etched. 
     
     
       10. The process of claim 1 wherein the substrate remains free of deformation or residue. 
     
     
       11. The process of claim 1 wherein the structure etched has a bottom surface that is atomically flat. 
     
     
       12. The etched structure resulting from the process of claim 1. 
     
     
       13. A method for determining small deviations from stoichiometry comprising scanning with an AFM a substrate area of known size, counting the resulting nucleation sites, and subtracting the number of nucleation sites from the number of atoms scanned.